Working with files in Python is pretty easy. But there’s a common mistake that can sneak into your code. Not closing the file ...

Note that the contents of the list need to be consistent for sorting to work. For instance, you can’t sort a mix of integers and strings, but you can sort a list that is all integers or all strings.

One more note: Python is ruthlessly obedient. If you just spent 20 hours running a program and you save the file as temp_data.txt. Then later you run something and save it as temp_data.txt - done.